Continuous filament slide fastener

ABSTRACT

A continuous filament for a slide fastener having legs extending from head elements and joined by flattened heels, the legs having notches therein at the junctions with the heels to seat threads for securing the continuous filament to a slide fastener tape and the heels extending substantially transversely from the surfaces of the notches, and a method and apparatus for forming the continuous filament.

United States Patent [1 1 Reynolds 1 1 Sept. 30, 1975 1 CONTINUOUSFILAMENT SLIDE FASTENER [75] Inventor: Rolfe E. Reynolds, Meadville, Pa.

[73] Assignee: Textron, Inc., Providence, R].

[22] Filed: May 10, 1973 [21] App]. No.: 359,051

[52] US. Cl. 24/205.l3 C; 24/205.16 C

[51] Int. Cl. A44B 19/10; A44B 19/40 [58] Field of Search 24/205.16 C,20513 C, 24/205.l C

156] References Cited UNITED STATES PATENTS 3,015,868 l/1962 Ruhrmann24/205.16 C

3,199.162 8/1965 Sohr i 24/205.16 C

3,579,748 5/1971 Chery 24/2051 C 3,757,391 9/1973 Cuckson 24/205.l C

FOREIGN PATENTS OR APPLICATIONS 2,027,193 3/1971 Germany 24/2051 C1,306,067 9/1962 France 24/205.13 C

1,529,317 5/1968 France 24/2051 C 1,177,727 1/1970 United Kingdom24/205.l C

Italy 24/205.13 C

Prinuu v ExaminerBernard A. Gelak [57] ABSTRACT A continuous filamentfor a slide fastener having legs extending from head elements and joinedby flattened heels, the legs having notches therein at the junctionswith the heels to seat threads for securing the continuous filament to aslide fastener tape and the heels extending substantially transverselyfrom the surfaces of the notches, and a method and apparatus for formingthe continuous filament.

2 Claims, 8 Drawing Figures Sheet 1 of 2 3,908,242

FIG. 4

US. Patent Sept. 30,1975

U.S. Patent Sept. 30,1975 Sheet20f2 3,908,242

CONTINUOUS FILAMENT SLIDE FASTENER BACKGROUND OF THE INVENTION 1. Fieldof the Invention The present invention pertains to slide fasteners and,more particularly, to a continuous filament forming interengagingelements for a slide fastener and a method and apparatus for forming thecontinuous filament.

2. Description of the Prior Art Continuous filaments made of a plasticmaterial are conventionally utilized to form interengaging elements forslide fasteners, such continuous filaments being normally of a coil-- orladder-type configuration. In securing ladder-type continuous filamentsto fabric slide fastener tapes, the threads extend over and protrudefrom the legs and heels of the continuous filament; and, thus, slidefasteners utilizing such continuous filaments are subject to wear andabrasion.

While the prior art has contemplated the use of grooves and recesses infilaments to reduce abrasion in slide fasteners, the prior art hasnotbeen well accepted due to difficulty in production and further sinceabrasion and wear have not been reduced to the extent desired. US. Pat.No. 3,015,868 is exemplary of specifically configured filaments forslide fasteners and means for securing such filaments to tapes; however,the threads utilized to secure the filaments to the tapes are stillexposed to wear and abrasion.

SUMMARY OF THE INVENTION The present invention is generallycharacterized in a slide fastener including a tape having an inner edge,a continuous filament forming a plurality of longitudinally spaced headelements, a pair of legs extending from each head element, a pluralityof flattened heels joining legs extending from adjacent head elementsand a notch formed at a junction between each of the legs and the heels,and thread means for securing the continuous filament to the tape, thethread means being seated in the notches.

Accordingly, it is an object of the present invention to produce acontinuous filament for a slide fastener overcoming the disadvantages ofthe prior art by utilizing notches in the legs of the continuousfilament adjacent flattened heels to seat threads for securing thefilament to a tape.

Another object of the present invention is to form a continuous filamentfor a slide fastener with flattened heels extending substantiallytransversely from the flat surfaces of notches formed in legs of thefilament.

A further object of the present invention is to provide a method offorming a continuous filament for a slide fastener wherein an angularlyoriented force is utilized to form a notch in the legs of the filament.

The present invention has an additional object in that apparatus forforming a continuous filament includes a forming wheel having cavitiesfor forming notches in the filament in response to an angular force froma sloping side surface of a heeling wheel.

Another object of the present invention is to utilize right-angledcorners to form notches and flattened heels in a continuous filament fora slide fastener.

Some of the advantages of the present invention over the prior art arethat threads securing the filament to a tape are biased toward thejunction of the legs and the heels to stabilize installation, theprofile of the tape and filament is reduced, protection is providedagainst scuffing by the slider and the threads securing the filament toa tape are contained and protected in notches adjacent heels extendingoutwardly to leave an unobstructed tape area.

Other objects and advantages of the present invention will becomeapparent from the following description taken in conjunction with theaccompanying drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation of a slidefastener having interengaging elements formed of continuous filamentsaccording to the present invention;

FIG. 2 is a section of the slide fastener of FIG. 1 taken along line 22;

FIG. 3 is an exploded view of apparatus for forming a continuousfilament according to the present invention;

FIG. 4 is a front elevation of the apparatus of FIG. 3 during forming ofa continuous element according to the present invention.

FIG. 5 is a broken perspective of a continuous filament according to thepresent invention;

FIG. 6 is a top view of a portion of the continuous filament of FIG. 5.

FIG. 7 is a side elevation of a portion of the continuous filament ofFIG. 5.

FIG. 8 is an end elevation of the continuous filament of FIG. 5 takenalong line 88.

DESCRIPTION OF THE PREFERRED EMBODIMENT each formed of a continuousfilament 22 and secured to the fabric tapes 12 and 14 in the samemanner. Accordingly, only elements 16 are shown in FIG. 2 to illustratethe manner in which the continuous filaments are secured to the inneredges of the tapes.

As shown in FIGS. 5-8, the continuous filaments 22 forming interengagingelements 16 and 18 are shaped to define head elements 24 adapted tointerengage when the slide fastener 10 is closed, a pair of legs 26 and28 extending from opposite sides of each head elev ment 24 and heels 30and 32 extending substantially parallel to the inner edges of the tapeson opposite sides thereof, heels 30 joining parallel legs 26 extendingfrom adjacent head elements 24 while heels 32 join parallel legs 28extending from adjacent head elements 24. Legs 26 and 28 have flatnotches 34 and 36 formed on the outer surfaces thereof adjacent heels 30and 32, respectively, and the heels 30 and 32 are each flattened to havea flat bottom surface and an oblate configuration with a longitudinalaxis extending substantially transversely from the notches 34 and 36,respectively, such that the continuous filament 22 is distorted in crosssection at the heels 30 and 32 as well as at notches 34 and 36 and headelements 24. As best shown in FIG. 5, a single complete course of thecontinuous filament 22 between two identical longitudinally spacedpoints, such as form A to B, includes a heel 30, a leg 26, a headelement 24, a leg 28, a heel '32, a leg 28, a head element 24 and a leg26 such that each course of the continuous filament 22 includes two headelements 24 and single heels 30 and 32 laterally spaced andlongitudinally alternating with each other. Accordinglyjthe continuousfilaments 22 have a plurality of heels 30 longitudinally spaced alongthe inner surfaces of the tapes l2 and 14 adjacentthe inner edgesthereof and a plurality of heels 32 longitudinally spaced along theouter surfaces of the tapes l2 and 14 in longitudinally alternatingrelation with heels 30;

As shown in FIGS. 1 and 2, the continuous filaments 22 are securedt'o'the tapes by thread or yarn 38 which can be either sewn or woven toextend over the legs 26 and 28 and loop around the extending portions toform a braid package. The thread 38 is seated in the notches 34 and 36such that the thread is protected from wear. With the continuousfilament 22 secured to the tapes, they are-bent about the head elements24 such that the flat surfaces of notches 34 and 36 slope angularlytoward the tapes and-the'legs 26 and 28 and heels 30 and 32 arepositioned against respective opposite sides of the tapes with the fiatbottom surfaces of the heels extending substantially perpendicular tothe flat surfaces of the notches 34 and "36; and, accordingly, thethreads 38 slide toward heels 30 and 32 during installation 'of thefilaments such that the threads are contained at the junctions of theheels and the notches providing the slide fastener with a low profileand positively preventing leg movement. The longitudinal axes of theflattened oblate configuration of the heels 30 and 32 extend at anoblique angle away from the tapes and head elements 24 providingprotection from scuffing by movement of the slider and leavingunobstructed areas of the tapes since the flattened cross sections ofthe heels extend outwardly at an oblique angle'away from the tapes andthe head eleof lugs 50 are carried on the peripheral surface of theforming wheel 40 on either side of channel 42, each lug 50 being inalignmentwith one of the guides 44 and 46 such that a front surface ofeach lug 50 spans the areabetween forming cavities '54 and 56 defined bythe spacing'between guides 44 and the spacing between guides'46,respectively. The bottom of channel 42 is defined by a spacer 48, andthe channel 42 has radial side walls 60 and 62 extending transverselyfrom the bottom of the channel to define theforming cavities 54 and"56between the guides 44 and 46, respectively, and

to 'form right-angled corners 63 and 64 with the periphof the legs 26and 28 of the continuous filament 22. The heeling wheel.65 has sidesurfaces 72 and 74 sloping from side rims 66 and 68 toward central rim70, respectively, the surfaces 72 and 74 having frustoconicalconfigurations with an angular orientation parallel to sloping surfaces48 on guides 44 and 46.

In orer to form a continuous filament 22 according to the' presentinvention, a continuous filament is initially formed in a serpentineconfiguration, for example by wrapping around the lugs 50, and is thenbent into a 'channel -like' configuration with'a generally constantfilament cros's 'se ction. The channel-like serpentine filarnerlt 76ispositioned'in the channel 42 of the forming wheel 40as'shown in FIG. 3with legs in forming cavities 54 and 56. The heelingwheel 65 is'insertedin channel 42, as shown in FIG. 4,'such that the filament 76 canbecontinuously' fed to the apparatus while the forming and heelingwheels 40 and 64 are rotated to compress the filamentand permitcontinuous forming of the continuous filaments 22. The heeling wheel 65is forced into the channel 42 with a force'sufficient to deform thefilament 76, the side rims 66 and 68 de pressing and flattening theheels 30 and'32 against the peripheral surface 41 of the forming wheeland the flat surfaces'52 of the lugs 50. The side surfaces 72 and 74 ofthe heeling wheel 65 provide an angular force pushin 'g'the legs offilament 76 into forming cavities 54 and 56 such that notches 34 and 36are formed in legs 26 and 28 by side walls 60 and 62, respectively, andcorners 63 and 64 provide the generally transverse or substantiallyperpendicular orientation between the flat bottom surfaces of heels 30and 32 and the flat inwardly extending surfaces of the notches 34 and36, respectively. The widened head elements 24 are formed by the spacesbetween guides 44 and 46 which permit the central rim of the heelingwheel 65 to slightly flatten andbend the transverse legs of the filament76. The parallel relation of sloping surfaces 48 and side surfaces 72and 74 permit the forming wheelto accommodate the heeling wheel withprecision positioning.

Inasmuch as the present invention is subject to many variations,modifications and changes in detail, it is intended that all mattercontained inthe foregoing description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is: V

In a slide fastener the combination comprising a tape having an inneredge and inner portions adjacent the inner edge;

a continuous filament having a length and forming a plurality oflongitudinally spaced head elements along its length, each head elementhaving'opposite sides, first and second legs extending from the oppositesides of each head element and being spaced relative to each other, afirst plurality of heels joining said first legs which extend fromadjacent head elements, a second plurality of heels joining said secondlegs which extend from adjacent head elements, the inner edge of saidtape being interposed between said first and second legs of the headelements along the length of said filament, a first notch formed at ajunction between each first leg and its associated first heel and on theexposed side of each first leg, a second notch formed at a junctionbetween each second leg and its associated second heel and on theexposed side of each second leg;

the first and second notches including opposed sloping surface means onthe first and second legs of a head element, the opposed sloping surfacemeans on each first or second leg of a head element being angularlyoriented in a direction toward said tape; and

thread means extending between and interconnected to inner portions ofsaid tape and the first and second notches such that said thread meansis seated in the first and second notches and said filament is securedto said tape;

said first and second pluralities of heels each having a flattened crosssectional configuration positioned first and second notches.

1. In a slide fastener the combination comprising a tape having an inneredge and inner portions adjacent the inner edge; a continuous filamenthaving a length and forming a plurality of longitudinally spaced headelements along its length, each head element having opposite sides,first and second legs extending from the opposite sides of each headelement and being spaced relative to each other, a first plurality ofheels joining said first legs which extend from adjacent head elements,a second plurality of heels joining said second legs which extend fromadjacent head elements, the inner edge of said tape being interposedbetween said first and second legs of the head elements along the lengthof said filament, a first notch formed at a junction between each firstleg and its associated first heel and on the exposed side of each firstleg, a second notch formed at a junction between each second leg and itsassociated second heel and on the exposed side of each second leg; thefirst and second notches including opposed sloping surface means on thefirst and second legs of a head element, the opposed sloping surfacemeans on each first or second leg of a head element being angularlyoriented in a direction toward said tape; and thread means extendingbetween and interconnected to inner portions of said tape and the firstand second notches such that said thread means is seated in the firstand second notches and said filament is secured to said tape; said firstand second pluralities of heels each having a flattened cross sectionalconfiguration positioned against respective opposite sides of the tapewith the longitudinal axis of the flattened configuration extending atan oblique angle away from the tape and the head elements.
 2. Acombination as recited in claim 1 wherein the opposed sloping surfacemeans of the first and second notches are sloped in a direction awayfrom the inner edge of said tape, and the first and second heels haveflat bottom surfaces extending substantially perpendicularly from theopposed sloping surface means of the respective first and secondnotches.